Clinical and Technical Factors Affecting pH and Other Biomarkers in Exhaled Breath Condensate
| Autor: | E. K. H. Liu, Christopher W.K. Lam, Gary W.K. Wong, Edmund Yung, Ting Fan Leung, C.Y. Li |
|---|---|
| Rok vydání: | 2005 |
| Předmět: |
Adult
Male Pulmonary and Respiratory Medicine Leukotrienes medicine.medical_specialty Adolescent Coefficient of variation Dinoprost Nitric Oxide Leukotriene B4 Severity of Illness Index pH meter Gastroenterology Immunoenzyme Techniques Disease severity Forced Expiratory Volume Internal medicine medicine Humans Exhaled breath condensate Cysteine Child Asthma Leukotriene business.industry Reproducibility of Results Hydrogen-Ion Concentration Intermittent asthma medicine.disease respiratory tract diseases Breath Tests Luminescent Measurements Pediatrics Perinatology and Child Health Exhaled nitric oxide Immunology Female Factor Analysis Statistical business Biomarkers |
| Zdroj: | Pediatric Pulmonology. 41:87-94 |
| ISSN: | 1099-0496 8755-6863 |
| DOI: | 10.1002/ppul.20296 |
| Popis: | Exhaled breath condensate (EBC) pH appears to be a robust measure of asthma. However, the association between EBC pH and clinical factors and airway inflammatory markers remains unclear. The objectives of this study were to investigate the factors determining EBC pH in asthmatic children, and the reproducibility and effects of collection devices on EBC pH in nine healthy, nonsmoking adults. EBC was collected once from asthmatic children using EcoScreen, and from adults over 3 consecutive days using both RTubes and EcoScreen. EBC pH was measured immediately in non-deaerated samples by microelectrode pH meter. Concentrations of 8-isoprostane, cysteinyl leukotrienes (cys-LT), and leukotriene B4 (LTB4) were measured using enzyme immunoassay. Exhaled nitric oxide concentration (FeNO) was measured by chemiluminescence. Fifty-eight asthmatics (16 intermittent, 12 mild persistent, and 30 moderate-to-severe persistent) were recruited. EBC pH was lower among patients with moderate-to-severe persistent than intermittent asthma (P = 0.046). This marker correlated inversely with disease severity score (ρ = −0.276, P = 0.036), but not FeNO or other EBC biomarkers. Bland-Altman analyses found pH but not other EBC biomarkers to be reproducible, which were confirmed by its low coefficient of variation (2.7%; range, 0.4–5.2%). There was poor correlation between pH in EBC collected by RTube and EcoScreen (ρ = 0.059, P = 0.784). Factor analysis selected four factors that explained 67.5% of the total variance, and EBC pH clustered with both cys-LT and LTB4. In conclusion, our results suggest that pH in non-deaerated EBC is influenced by asthma severity in children. EBC pH measurement is reproducible, but is dependent on the collection devices used. Pediatr Pulmonol. © 2005 Wiley-Liss, Inc. |
| Databáze: | OpenAIRE |
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